This invention relates generally to security systems, and more particularly to using an arm/disarm device to arm and disarm the security system.
Keypads are often located at secured doors and may be used to enter in codes to arm and disarm a security system. A keypad transceiver is used to communicate with the control panel of the security system. The keypad transceiver and associated electronics are in an ON or activated state to constantly scan for input from the surrounding, environment. Radio frequency identification (RFID) readers are often incorporated into the keypads for reading RFID tags or keytags that are carried by users of the system and, used to arm and disarm the system. The RFID tags may be active tags that are battery powered or passive tags that are powered by the RFID reader. Active tags transmit. RF packets at regular intervals at relatively high power, consuming approximately 25 milliamps (mA) or more per transmission. This shortens the life of the active tag.
It is often desirable to have the keypad communicate wirelessly with the control panel of the security system. In such a wireless environment, the keypad may be battery powered. For a typical RFID reader circuit, the transmit current may be close to 70 mA. Therefore, the RFID reader cannot be turned on all the time as the battery life would not be acceptable for a typical wireless application. However, the RFID reader has to be ON or activated to detect the RF packets, as well as to power the, passive tags if needed.
Battery life of the RFID reader may be conserved by having a user press a key on the keypad to wake up the RFID reader. The user may then present the RFID tag close to the RFID reader, or some RFID tags may be read or sensed while in the user's pocket, purse, backpack and the like. However, it is desirable for the keypad to conserve battery power while sensing the RFID tag without the user having to go through the extra step of pressing a button to initiate the operation.